Skin barrier product with discontinuous adhesive layer

ABSTRACT

An adhesive, flat skin barrier product for use as semi-manufacture in the production of, a.o., dressings, wound-care devices, electrodes and fastening means for ostomy equipment and catheters, consists of alternating zones of material of at least two different kinds (26,28,30) at least one of which is a skinfriendly self-adhesive material. The zones are parallel and extend in a direction usually at right angles to the main surfaces of the product. The zones may for instance be parallel strips, co-axial rings, co-wound Archimedean spirals or short strands. 
     The skin barrier product offers the advantage that in a simple way it may be produced to comprise, besides the sealing material itself, other components for special purposes, e.g. having contents of antiseptics, medicaments or others biologically active substances of liquid-transporting or electrically conductive structures.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to an adhesive, flexible flat skin barrierproduct for use as a semi-manufacture in the production of dressings,skin and wound care devices, fastening means for dressings, ostomyequipment, wound drains and catheters, e.g. for incontinence equipmentfor men and for similar applications, and for use in electrodes forapplication to the skin.

A large number of flexible skin barrier products of this general typeare known, and many of them have as a main component a sealing materialcomprising a continuous phase containing an adhesive and for instancebeing built from an elastomer, an emulsifier for the elastomer, a resinpromoting the adhesive capacity and optionally an oil-based extender aswell as an antioxidant. In this there is in many cases dispersed adiscontinuous phase comprising one or more water-soluble orwater-swellable hydrocolloids, starch derivatives or cellulosederivatives or hydrophilic polymers.

Examples hereof are those known from U.S. Pat. Nos. 4,231,369 and4,367,732. They consist of a continuous phase comprising a physicallycross-linked elastomer in the form of one or more styrene-olefin-styreneblock copolymers or ethylene-propylene block copolymers, a hydrocarbontackifier in the form of a polymer or copolymer from cyclopentadiene,dicyclopentadiene, α-pinene and/or β-pinene, an antioxidant andoptionally a liquid paraffin as an emulsifier; and in this adiscontinuous phase comprising one or more water-swellablehydrocolloids, preferably gum guar and/or sodium carboxymethylcellulose. Known skin barriers may also contain other elastomers, e.g.natural rubber, synthetic resins of a similar nature as natural rubberand silicone rubbers. As adhesive material and structure-formingcomponent in skin barriers polyisobutylene of a suitable molecularweight distribution is also frequently used, e.g. as stated in U.S. Pat.No. 3,339,546. In principle, all known skin-friendly self-adhesivesealants may be present in the skin barrier product according to theinvention.

In the majority of the known skin barriers the composition thereof issubstantially uniform over the whole of the width and length dimension(hereinafter sometimes together called the surface dimension, i.e. seenas passing from one edge to an opposite edge thereof), incidentally as arule also in the thickness dimension, as regards the adhesivecomposition. This is often an advantage but in a number of instancesvarying properties in the surface direction may be desirable, forinstance in such a way that regions or portions of adhesive materialforming an angle to the flat surfaces of the product alternate withregions or portions of another kind equally forming an angle to thesurfaces of the skin barrier product, e.g. made of another kind ofadhesive material, of less adhesive or of non-adhesive material; ormaterials having more or less pronounced barrier properties, havingliquid-conducting or electrically conducting properties, materialscontaining wound-healing substances or medicaments, or absorbingmaterials.

U.S. Pat. No. 3,885,559 discloses a process for the reduction of pain inthe removal of adhesive tapes or bandages. This is achieved by using anadhesive tape or bandage comprising a flexible backing with an adhesiveportion distributed and adhered thereon in the form of adhesive layersalternately spaced with regions of lesser or even no adhesiveness. Thebacking is needed to hold the regions assembled, and the individualregions do not extend through the entire thickness of the product, viz.because of the backing.

European published Patent Application No. 134,437 A1 discloses aflexible magnetic foil for therapeutic purposes. It has a flexiblerubber-like foil in which permanent magnetic ferrites have beenembedded, whereby the active surface of the foil has been magnetizedwith poles having alternating polarity. In order to attach the foil tothe skin of a patient, it is provided with self-adhesive coating whichis tolerable to the skin. Thus, no kind of material extends through theentire thickness of the product.

SUMMARY OF THE INVENTION

It is the object of the invention to provide a semi-manufacture skinbarrier product with properties changing in the width and/or lengthdimension so as to suit varying needs with one product not needing someuniform cover layer or backing unless the ultimate use of thesemi-manufacture calls for the application of such a uniform layer on asurface of the product. According to the invention this is achieved ifthe product consists of a number of alternating zones of material of atleast two different kinds, at least one kind of zone consisting of askin-friendly self-adhesive material, the zones of material extendingsubstantially parallelly through the entire thickness of the product ina direction intersecting its flat surfaces. Preferably the zones aresubstantially at right angles to the flat surfaces of the product andhence are parallel to the edges. All the kinds of material present inthe product have to be substantially non-irritating to skin or mucousmembranes and must also be substantially non-allergenic.

According to the invention at least one kind of zone consists of aself-adhesive material of the kind which comprises a continuous phasecontaining a self-adhesive elastomer mass and one or more water-solubleor water-swellable hydrocolloids substantially evenly dispersed as adiscontinuous phase in the continuous phase. The self-adhesive sealingagent may thus advantageously be one of the kinds described in theabovementioned U.S. Pat. Nos. 4,231,369 and 4,367,732 and which in thecontinuous phase also comprise an emulsifier for the elastomer andnormally an antioxidant.

The self-adhesive material or one of them may, however, have no contentsof hydrocolloid and, e.g., be based on styrene-isoprene-styrene blockcopolymers, polyisobutylenes, polyvinylether or polyacrylates,polymethacrylates or copolymers thereof.

The skin barrier product preferably has the same thickness as known skinbarriers, for instance 0.5-2 mm.

DETAILED EXPLANATION OF THE INVENTION

The various zones of material may be grouped in various ways.

In principle, thus, one or more zones may be entirely surrounded at alledges by one or more other zones, said other zones being of mutuallydifferent or identical materials. The geometrical arrangement may varywidely. Thus, as seen from the surface, one zone of one material mayform an "island" in a matrix formed by another material; or a pluralityof zones of the same material or different materials may form suchislands in the matrix. Also, a plurality of thin platelets made ofmaterials of two or more kinds and having irregular or regular shapesmay be joined together so as to fill up the semi-manufacture.

According to another variant, two or more kinds of material are spirallywound together to form (two or more) neighbouring zones eachsubstantially in the shape of an Archimedean spiral which may, howeverbe more or less deformed. Such a product may be formed by stackingsheets or lengths, each having a constant thickness, of the desiredmaterials, rolling the stack as one rolls a carpet and slicing the rollthus formed substantially perpendicularly to its axis.

In a further geometrical arrangement of the product according to theinvention, the zones of material, seen from the surface of the product,are rectilinear, curved or wavy, substantially parallel and all extendfrom one edge of the product to another. It will be understood that eachindividual zone, be it rectilinear, curved or wavy, has a substantiallyconstant width, i.e. that its edges, bordering a neighbouring zone orthe outer world, are substantially equidistant.

A variant of this embodiment is one in which all of the zones form aclosed curve, e.g. a circle or an elliptic curve, seen from the surfaceof the product. In that case the zones are cylinders of, for instance, alength of 0.5-2 mm, a central cylinder being in its entirety surroundedby one or more other and larger cylinders. Any two adjacent zones orcylinders consist of different materials. Such cylinders may bedeformed.

A further variant is one in which the zones of material, seen from thesurface of the product, are rectilinear, curved or wavy, substantiallyparallel and all extend from one edge of the product to another, atleast one such zone having a function other than an adhesive function.Any zone having a function other than an adhesive function may wellhave, but need not have, that other function in addition to an adhesivefunction. For example a medicament or some liquid-transported structuremay be embedded in an adhesive material.

Thus, in the present product the zones may be mainly parallel orco-axial alternating strips of identical or different thicknesses. Inthat case the product is a sort of laminate the layers of which arequite short and upright or at least form an angle to the main faces ofthe product. Preferably the strips may have a thickness of for instance0.5-2 mm, whereby they are easily produced by slicing from a roll or astack of layers of a usual skin barrier, alternating with layers of adifferent material. The zones may, however, also be thicker, especiallyin annular semi-manufactures of the kind in question, for instance 1-5cm. In this case the skin barrier product may for instance be producedby extrusion, a process which may also be used in the production of aproduct having narrow zones, and subsequent slicing into thin sheets.

According to the invention at least one of the kinds of zones may bemade of a material hampering or preventing migration of matter to andfrom adjacent self-adhesive zones. In other words it is a question of amore or less efficient barrier zone. These barrier zones may be ofseveral different kinds and their presence does not exclude the presenceof zones of quite another kind in the product.

This embodiment notably has importance in cases where zones of theself-adhesive sealing agent alternate with zones of another kind and itis wanted to prevent migration of matter from or into said zones ofanother kind. At least one of the kinds of zones may consist of amaterial hampering or preventing passage of aqueous liquids to adjacenthydrocolloid-containing self-adhesive materials.

The zones hampering or impeding migration of matter may for instance befilms or foils of plastic or metal. Such barrier foils or films may forinstance have a thickness of 10-100 μm and for instance consist ofpolyolefins, polyester, poyvinylchloride, aluminium or laminatesthereof.

The zones hampering or preventing migration of matter couldalternatively consist of a material which is ductile under the influenceof low forces and also more or less hydrophobic and containing aself-adhesive elastomer mass, but no hydrocolloid. A main function ofself-adhesive skin barriers containing hydrocolloid is to absorb sweatand/or wound exudates while retaining their adhesive capacity. Due tothe absorption capacity thereof, such skin barrier product may, however,unwantedly absorb liquid from the edges, for instance water from bathingor secretion from stomas in case of its application for fastening ostomyequipment. When it comprises a material hampering migration of matterand especially a material hampering migration of water, the movement ofthe water across the edges of the zones of the skin barrier product (amovement parallel to its flat surfaces) will become very slow and theproduct will retain its adhesive capacity for a long period of time andthus obtain an increased life time. When the adhesive material withoutor poor in colloids is ductile under the influence of low forces, itwill keep up with the thickness increase of the product and therebystill form a barrier against unintentionally being decomposed by waterfrom the edges.

Since moreover materials of the kind in question may be composed in amanner so as to absorb water to a certain degree, but substantiallyslower than does the hydrocolloid-containing adhesive, it will be ableto keep up with even very considerable increases in volume caused by theabsorption of liquid.

Although the zone hampering migration of matter generally does notcontain hydrocolloid, it is possible that zones of adhesive material ofthe kind in question and having a high content of hydrocolloid alternatewith zones having a lower content of hydrocolloid instead of zonesentirely devoid of hydrocolloid.

In another grouping of the zones of material they may in accordance withthe invention be strands of identical or different cross-sectionalshapes and sizes and substantially fill up the product. The lengths ofthe strands are normally the thickness of the product so that they areat right angles to the main surfaces thereof, but they may also belonger and thus be at an oblique angle to the main surfaces of theproduct and the edges thereof.

The strands may have any regular or irregular cross-section, but shouldfill up the product so that there will be no air ducts where they abuton each other. They may be prismatic and thereby in a simple mannerfulfil the requirement for filling up the product if theircross-sections are either identical equilateral triangles, squares orregular hexagons. Normally they will, however, be round strands. A skinbarrier product having its zones in the form of strands may be producedby co-extrusion of for instance prismatic, circular or oval, long,parallel strands of the materials in question, and subsequent slicing ofthe composite strand thus formed into thin pads. If the cross-sectionsof the strands do not by themselves ensure the complete filling up ofthe cross-sectional area of the product formed, one may after theextrusion but before the slicing press the single strands together intoa composite strand, for instance by passing them through a slightlyfunnel-shaped compressing device.

At another grouping of the zones of material a number of strands aredistributed evenly or unevenly in a strand of a self-adhesive materialof the kind comprising a continuous phase containing a self-adhesiveelastomer mass and a water-soluble or water-swellable hydrocolloiddispersed therein as a discontinuous phase, said latter strand fillingup the interspaces between the former. The distribution may possiblyalso be the opposite: single strands of an adhesive material asmentioned, distributed in a larger strand surrounding all of them andforming a sort of matrix for them.

In the embodiment having the single strands distributed in a surroundingstrand there may be strands of various kinds, i.e. strands of mutuallydifferent kinds, for instance the kinds referred to later in thisspecification.

The skin barrier product according to the invention may advantageouslybe in the form of an annular pad for affixing drains, ostomy pouches orother equipment, in which case according to the invention thealternating zones of material may be substantially co-axiallycylindrical or form an Archimedean spiral, and the product may beprovided with a central aperture. Further, the product may be providedon both the inner edge and the outer edge with a water-impermeablebarrier layer, such as e.g. a film or foil of plastic or metal or alaminate thereof, or of a self-adhesive elastomer mass free fromhydrocolloid or poor in hydrocolloid. It is thereby attained that waterfrom the outer edge or secretion from stomas from the inner edge onlyslowly penetrate into the adhesive ring whereby the lifetime thereofwill be substantially increased.

Such products may be produced in a far more economic way than currentannular pads, which are manufactured by punching from sheets or lengths,thus causing a considerable waste of material. In contradistinctionhereto an annular product as just mentioned may be manufactured byco-extrusion of materials for the zones to form a hollow cylinder havingco-axial layers of material and subsequent slicing of the cylinder thusformed; or by spirally coiling assembled lengths of the materials andsubsequent slicing of the hollow roll thus formed.

It is observed that by the expression "annular" reference is made to anyembodiment of the product having a defined outer delimitation and acentral or eccentric aperture suitable for engaging a drain or a stoma.The aperture needs not be circular but most frequently is. The outershape may be circular, elliptic or polygonal, e.g. quadrangular, or haveany other desired shape. Even products having an outer shape differingfrom that of the circle may be produced in the manner described above,most conveniently by performing a suitable deformation before the hollowcylinder or roll is sliced; a desired shape of the aperture may bemaintained by means of a mandrel which is removed successively as theslicing proceeds.

An annular product may conveniently comprise zones that hamper orprevent migration of matter or contain a self-adhesive elastomer massfree from hydrocolloid or poor in hydrocolloid, and such zones mayadvantageously form the outer zone and/or inner zone; but mayadditionally be partition zones within a hydrocolloid-containingself-adhesive elastomer mass.

A long series of other materials may form parts of the product accordingto the invention, either as separate zones or as parts of zonescontaining an adhesive. As examples may be mentioned that one or morekinds of zones expediently may consist of a foam material having open orclosed cells. In the foam material a biologically active substance maybe present, for instance a medicament or an antiseptic or antibiotic.The biologically active substance may be present within the cells of afoam with open cells or be present in the very foam material, i.e. as acomponent of the walls of open or closed cells which for instance mayconsist of a foamed gel material such as gelatin.

Biologically active substances may also be present in other materialsthan foam materials. For instance one or more zones of material maycomprise hydrophilic gel substance containing an agent effective againstwarts, e.g. cantharidine, salicylic acid, silver nitrate, podophyllin,or an anti-metabolitic cytostatic such as cytarabine, fluorouracil ormercapto-purine.

One or more zones of the product may be made from a hydrophilic gelsubstance containing one or more keratolytically active substances, forinstance carbamide, salicylic acid and/or lactic acid.

Furthermore, one or more zones may for instance contain one or morecompounds inhibiting mitosis, e.g. anthracene, silver nitrate orglucocorticoids such as mildly, medium strongly or strongly activecorticosteroids such as hydrocortisone, triamcinolone acetonide orbetametasone.

The gel substances mentioned above may be hydrophilic or hydrophobic,optionally of a desired HL-balance (hydrophilic-lipophilic balance), andoptionally a supporting structure may be incorporated therein in theform of a foam of, e.g.,a polyether, collagen or gelatin, or in the formof fibres, filaments or woven or nonwoven textile material, e.g. of apolyester or cotton. Hydrophilic gels may for instance be mixtures ofkaraya and glycerol; of pectin, lower molecular weight polyethyleneglycol and glycerol; or mixtures of gelatin, glycerol and water.

Hydrophobic gels may for instance consist of mixtures ofstyrene-isoprene-styrene blockcopolymers and paraffin; mixtures ofstyrene-isoprene-styrene blockcopolymers, liquid paraffin anddioctyladipate; or mixtures of nitrocellulose, ricinus oil and rosin.

As examples of active substances which may be incorporated into the gelsubstances may be further mentioned antiseptics such as iodophors,silver compounds, hexidine or chlorohexamine; vitamins; and antibiotics,wound-healing agents and growth-promoting substances.

Foam materials which may be present as a special kind of zone or form asupporting structure in the gel substances just mentioned, may forinstance be of a polyether, polyethylene, polyvinyl chloride, gelatin orcollagen.

The skin barrier product according to the invention may further compriseliquid-transporting structures. They may for instances be fibres,filaments or woven or nonwoven textiles; and optionally tubularstructures may be present in the form of capillaries or bodies havingducts, the capillaries or ducts being substantially at right angles tothe surfaces of the skin barrier product. Bodies containing ducts mayfor instance be of plastics or rubber-like materials.

The skin barrier product may also incorporate layers with so-calledsuperabsorbing materials; such materials are well-known in connectionwith absorption products such as sanitary towels and diapers.

According to a special embodiment of the skin barrier product itcomprises zones or strands of (a) a self-adhesive material preferablywithout hydrocolloid and (b) a hydrophilic, electrically conductive gelsubstance, optionally separated by an aluminium foil. This embodiment isespecially suitable for the production of electrodes for use intransneurocutaneous stimulation (TNS). Contrary to electrodes forelectrocardiographs, which transmit specific voltage differences, theTNS-electrodes should only be electrically conductive and this isachieved by means of the conductive gel substance which is preferablythe more structure-forming component in this embodiment. It possessesthe advantage of utilizing self-adhesive technology proper so that anelectrode manufactured therefrom because of the self-adhesive zones maybe fixed in a given position for many days.

The electrially conductive gel may be a hydrophilic basal polymer suchas polyacrylamide, salts of polymethacrylic and polyacrylic acids,polyvinyl alcohol or Na-CMC, softened by means of an emollient of lowviscosists, e.g. a liquid polyol such as glycerol and optionally with anaddition of typically 0.1-1.5% of NaCl, KCl or another biologicallyharmless, readily soluble salt and if desired 1-10% of water.

A product of this kind is preferably made from a stack of alternatingsheets or lengths rather them from strands. The zones in the finishedproduct of the invention may be straight, curved or wavy, but mayespecially be approximately circular. In that case, the product may bemade from a stack as alternating layers in the same manner as describedin connection with the annular products, only omitting the aperture inthe middle. The production may be performed in analogy with thatdescribed for the annular products.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the skin barrier product according to the inventionwill be described more fully with reference to the drawing. In thedrawing

FIGS. 1-5 show cuttings from five different embodiments of the productaccording to the invention, seen from the surfaces thereof,

FIG. 6 in larger scale shows a section along the line VI--VI in FIG. 1(in principle even a partial section of FIG. 9),

FIG. 7 a similar section as FIG. 6, but of the embodiment according toFIG. 2, and

FIGS. 8-9 two different embodiments of the skin barrier productaccording to the invention and suitable for use in securing an ostomypouch and seen from the surface.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

FIGS. 1 and 6 show a skin care product 10 consisting of alternatingstrips or zones 18 and 20 of material, all extending in a directionsubstantiallyperpendicular to the surfaces of the product. They areshown as flat, rectilinear strips but might for instance be curved orwavy. As shown theyare also substantially parallel, which here as inother parts of the specification means that the individual layers havesubstantially equidistant boundary surfaces or edges 22.

The zones 18 consist of an agent adhesive to the skin and comprisinghydrophilic components, especially of the kind consisting of acontinuous phase containing a self-adhesive elastomer mass and one ormore hydrocolloids dispersed therein as a discontinuous phase. The zones20 consist of a continuous phase of a self-adhesive elastomer mass,preferably of the same kind as in the zones 18, but without anyhydrophilic discontinuous phase. Thus the zones 20 will act as barrierswhich to a high degree will counteract migration of aqueous liquids fromthe zones 18 to the zones 20. The zones 20 do not, or only to a smalldegree, absorb water from the skin or wound surface to which a finishedproduct produced from this semi-manufacture is attached.

The skin care product shown in FIGS. 1 and 6 may be produced byalternatelyjoining long strips of material 18 and material 20 to form ablock which issubjected to light pressure to ensure full contact betweenthe surfaces of the layers, after which the block is sliced into padshaving a thickness of, e.g., 0.5-2 mm. It is expedient that the widthsand numbers of the strips correspond to the desired surface dimensionsof the product. It is observed that the thickness dimension shown inFIG. 6 is not necessarily correct relative to the length dimension. Thelines 24 in FIG. 6 mark surfaces, but might as well represent detachableprotective covers, for instance of siliconized paper, which may beplaced on the semi-manufacturebefore it is worked up to form a finalproduct.

Slicing of the block of layers 18,20 may be carried out with a cuttingwirebut preferably takes place with a knife the sides of which areconstantly moistened with a solvent which does not affect the materialsof the block and which evaporates rapidly after the cutting. When theskin adhesive is one of the kinds described in the U.S. Pat. Nos.4,231,369 and 4,367,732 ethanol or isopropanol is preferably used as thesolvent.

FIGS. 2 and 7 show a skin barrier product 11 also built up fromparallel, rectilinear thin zones 26 and 28. The zones are of differentwidths and can optionally be separated by barriers of foil 30. The zones26 consist of a skin adhesive material of for instance the same kind asthe zones 18 or 20 in FIG. 1. The zones 28 consist of or contain amaterial active in some desired respect, here exemplified by anelectrically conductive, hydrophilic gel material; in that case thezones of elastomer mass 26 preferably do not contain hydrophiliccomponents and the barriers of foil 30 are preferably of aluminium. Theelectrically conductive material may for instance consist of karaya,glycerol, propylene glycol, NaCl and waterin the weight ratio42:53:3:0.25:3; or polyacrylate, glycerol, water and NaCl in the weightratio 62:36:2:0.15; or polyoxyethylene, propylene glycol, water NaCl andKCl in the weight ratio 11:45.5:43:0.45:0.05; or gelatin, glycerol,water and NaCl in the weight ratio 47:47:4.8:1.2.

The skin care product 12 shown in FIG. 3 consists of two alternatingkinds of zones of material, viz. zones 32 of a skin adhesive, forinstance of the same kind as the zones 18 in FIG. 1, and zones 34 of amaterial particularly suitable for transporting liquid through thethickness dimension of the product, viz. perpendicular to the plane ofthe paper. The structure permitting the transportation is shown ascapillaries 36 butthe transportation capacity may also be caused by,e.g., an open-cell foam material constituting or forming part of thezones. The capillaries may beincorporated into a hydrocolloid-free skinadhesive of, e.g., the same kindas the adhesive in zones 20 in FIG. 1 sothat liquid will not migrate in the surface direction of the product.This product is especially suitable for the production of dressings forsuppurating wounds. Migration of liquids parallelly to the surfaces mayalso be prevented by impermeable barrier layers, for instance foilsbetween layers 32 and 34.

The products shown in FIGS. 2 and 3 may be produced in the same way asthatshown in FIG. 1.

On the other hand, FIG. 4 shows a skin care product 13 built up andproduced in another way. Its zones are short prismatic strands40,42,44,46extending in a direction intersecting the surface of theproduct and being of two or more different kinds. Such a product isproduced by extruding long strands of the respective kinds of materialthrough nozzles, then preferably through a funnel-shaped tube in orderto ensure that there willbe no airfilled interstices between thestrands, and subsequent slicing of the composite strand thus formed intothin pads. It will be understood that the final semi-manufacture willnot have planar boundary surfaces between the strands as shown for thesake of clearness. Instead of being prismatic the nozzles may be roundand of identical or different sizes, just as the prismatic strands mayall have the same size and may advantageously have the cross-section asequilateral triangles, squares orregular hexagons. The slicingpreferably is carried out at right angles to the longitudinal dimensionof the long strands but might be oblique thereto.

In the product shown in FIG. 4 the strands 40 of skin adhesive are ofthe same kind as are the zones 18 in FIG. 1; the strands 42 areliquid-transporting as are the zones 34 in FIG. 3, preferably withcapillaries embedded in a hydrocolloid-free skin adhesive; the strands44 consist of a hydrocolloid-free adhesive like the zones 20 in FIG. 1;and the strands 46 contain a substance biologically active in skin care,e.g. an antiseptic or antibiotic, a growth-promoting agent or awound-healing agent.

The skin care product 14 shown in FIG. 5 contains a plurality ofcomparatively wide circular-cylindrical strands 50 of a skin adhesive ofthe same kind as that of the zones 18 in FIG. 1, viz. a self-adhesiveelastomer mass containing a hydrocolloid embedded in a common strand 54consisting of a skin adhesive of the same kind as that in the zones 20in FIG. 1, i.e. without a hydrocolloid or with a low content ofhydrocolloid.

This product may be produced by extrusion through a nozzle for thematerialfor the strand 54 containing channels through which the materialfor the strands 50 is conveyed.

It will be appreciated that the strands referred to in FIG. 4 and 5 arequite short, i.e. as the thickness of the product.

FIG. 8 shows an annular skin barrier product for use in the productionof ostomy appliances. It consists of three annular zones of material,outer and inner zones 56 of a skin adhesive of for instance the samehydrocolloid-containing kinds as the material of the zones 18 in FIG. 1,and therebetween a hydrocolloid-free zone 58. Inside the inner zone 56there is an aperture 60, and penetration of liquids from said apertureto the inner zone of sealing agent 56 is prevented by a cover ofliquid-tightfilm or foil 62; the entire annular product is encased in acorresponding liquid-barrier 64.

The number of annular zones may be greater, and annular zones consistingofor comprising other materials may also be present, e.g.,liquid-transporting zones or zones containing biologically activesubstances.

An annular product as shown in FIG. 8 may be produced by co-extrusionand slicing.

Another embodiment of an annular skin barrier product is shown in FIG.9. The zones of material here are in the form of layers 66,68 ofArchimedean spirals surrounding a central aperture 60. There are twosuch "co-current"spirals extending from an inner end to an outer, butthere might be more. One of the spirals 66,68 consists of ahydrocolloid-containing adhesive asthat in the layer 18 in FIG. 1, theother of a hydrocolloid-free material of the same kind as that in thelayer 20 in FIG. 1. Innermost adjacent theaperture 60 and outermostfacing the outer world a barrier foil or film as the foils or film 62,64in FIG. 8 may be provided.

This product may be produced by uniting two wide lengths correspondingto the zones 66 and 68, optionally providing the laminate thus formedwith barrier foil or film on one side, and winding them around asuitable cylindrical object on which the roll may slide. Then the rollis moved forward in its length direction (the width direction of thelengths) and is sliced into thin pads just in front of cylindrical core.It will be understood that the ring formed may nave a barrier foil forevery two layers, seen radially. The line 74, however, only marks theboundary surface between the two spirals, but might also represent abarrier foil.

By producing blanks for sealing rings for ostomy pouches as explained inconnection with FIG. 8 and FIG. 9 there is achieved the advantage ofavoiding the waste of material that will inevitably occur in the knownproduction of such sealing rings by punching from sheets or lengths oftheskin adhesive.

By rolling into spirals and slicing, an electrically conductive skinbarrier product may be advantageously produced. In that case one of thelayers of material 66,68 consists of a self-adhesive elastomer massmainlyof hydrophilic components, and the other of an electricallyconductive, hydrophilic gel material as described hereinbefore. A thinaluminium foil may further be placed between the lengths of material.

In order to prevent flow of the edges the skin barrier productsdescribed may be bevelled along their edges as described in Europeanpatent application publication No. 264,299.

EXPERIMENTS

In the field of ostomy bandages the so-called two-piece bandages gain anincreasing popularity, i.e. for economic reasons because it is possibletochange and discard the parts at different frequencies.

In two-piece ostomy equipment an ostomy bag or ostomy stopper is firmlyattached to one member of an annular two-part coupling ring and a skinbarrier and sometimes also other equipment firmly attached to the other.The rings can be hermetically united to each other by some snap-likeclosing structure and comparatively easily disjoined from each other.Thus, during function the skin barrier keeps the bag or stopper in placearound or in the ostomy opening. Numerous examples of such ring couplingsystems are known, e.g. from European patent application publication No.188,776 (FIG. 7) and Danish patent specification No. 151,044correspondingto U.S. patent application Ser. No. 987,523 of May 27,1986.

In such two-piece systems the part with the ostomy bag or stopper mustnecessarily be discarded and replaced frequently, commonly several timesaday, whereas there is no reason to replace the skin barrier with itscoupling ring as long as the skin barrier itself is intact.

Adhesive materials as those described in the introducing parts of thepresent specification and disclosed in, i.a. U.S. Pat. Nos. 3,339,546,4,321,369 and 4,367,632, normally function excellently for periods ofone to two days, but during the period following that the juicesescaping fromthe ostomy opening will usually penetrate into the skinbarrier and cause it to leak, which is very unpleasant for the user ofthe ostomy closing system.

By experiments it has been shown that a skin barrier according to thepresent invention will greatly prolong the lifetime of the coupling partprovided with the skin barrier and belonging to a two-piece ostomysystem.

A. 1. An adhesive mass as described in the Example of U.S. Pat. No.4,367,632 applied as a melt to a thickness of 1 mm on siliconized paperand a film of EVA (ethylene-vinylacetate copolymer) having a thicknessof 70 μm was laminated onto its free surface. From this there was in theusual manner punched circular discs having an outer diameter of 100 mmandvarying inner diameters (25 to 50 mm, individually adapted to thesizes of the stomas of the volunteers participating in the tests). Thecenter partsand the material between the discs were discarded as wastematerial.

A. 2. The same kind of adhesive mass as above was applied as a melt to athickness of 1.5 mm to a length of siliconized paper. Another adhesivemass, having the same composition as the first one except for itscontent of hydrocolloid (30% Na-CMC) was applied as a melt to athickness of 0.5 mm onto another length of siliconized paper.

The two lengths, each having a width of 1 meter, were wound together,the surfaces not provided with the siliconized paper facing each other,while pulling the siliconized papers off. In this manner there wasformed 1 m long cylinders having an outer diameter of 100 mm; thewinding was made around re-usuable cylindrical, silicone -coated rods ofvarying diameters (25-50 mm) to accommodate various sizes of stomas. Theresult was a spirally coiled roll having a cross-section largely as thedisc shown in FIG. 9 of this specification. The layers of the rollalternated throughoutits thickness between layers with and layerswithout hydrocolloid in the adhesive mass.

The roll was sliced into annular discs each having a thickness of 1 mmby the aid of a specially designed slicing machine with a rotating steelblade which was constantly moistened with ethanol from a felt pad. Themachine could cut 60 such discs per minute.

The machine was adapted to catch the thin, flexible discs formed (whicheach is a skin barrier product according to the invention on a sheet orlength of EVA film which may serve as a carrier or packing material forthe product or may even be a part of an ultimate product produced fromthesemi-manufacture.

It should be noted that the hydrocolloid-containing adhesive mass lostits self-adhesive properties in the surface immediately upon the cuttingoperation because the particles of hydrocolloid appeared in the verysurface. After storage, however, the material regained its surfaceself-adhesive properties. The 0.5 mm zones of hydrocolloid-free adhesivemass sufficed to permit the immediate adhering to the EVA film and othersuitable surfaces.

A. 3. Thereafter both types of skin barrier, 1 and 2, were worked upwith aring coupling to form a stopper system as illustrated by FIG. 7 inEuropeanpatent application publication 188,776 (Danish patentspecification No. 153,122).

The two stopper systems were comparatively tested by 25 colostomypatients who were users of such stopper systems.

A significant difference was found between the two different kinds ofskin barriers. Skin barriers No. 1, that comprising only thehydrocolloid-containing adhesive, could be used in average onlyapproximately 2 days, whereas skin barrier No. 2, that comprisingalternating zones of hydrocolloid-containing and hydrocolloid-freeadhesive could be used in average about 10 days.

B. Another experiment was made with 20 volunteers who were accustomed tousing ileostomi bags attached to the body by the aid of a skin barrieraccording to A. 1. above.

The test skin barriers were made to dimensions as described under A.2.above, but with alternating zones, viz. 1 mm wide zones of ahydrocolloid-free adhesive mass as described under A.2., alternatingwith non-self-adhesive zones (3 mm wide) of gelled karaya/glycerol 1:1.

The preparation took place in analogy to what is described in U.S. Pat.No.4,062,261 (DK 132,645), only with the difference that the elastomermixturethere shown was replaced by the abovementioned self-adhesivemass. In this process the sheet material, having a width of 1 meter,only had to be wound alone while at the same time removing a singlesheet of siliconized paper.

The skin barrier product was confectioned as described under A., andtestedby use in a two-piece bag system with an ileostomy bag mounted bythe aid of a two-piece coupling.

Again, there was found an outspoken improvement of the lifetime of theskinbarrier in comparison with that of the usual skin barrier. Moreover,the users much appreciated the presence of karaya which is known as anextremely skin-friendly material but which suffers from theinconveniency that it disintegrates too quickly.

INDUSTRIAL USE OF THE INVENTION

It is expected that the invention will attain an almost immediate use inthe manufacture of skin barriers for attaching ostomy equipment, drainsand catheters to the human body; and later also in highly specializedskinand wound care products.

What is claimed is:
 1. In an adhesive, flat skin barrier product havinga flat surface adapted to come into contact with the skin and anopposite flat surface, for use as a semimanufacture in the production ofdressings, skin-and wound-care devices, electrodes for application tothe skin, fastening means for dressings, ostomy equipment, wound drainsand catheters, the improvement wherein said product consists of aplurality of alternating zones of at least two different kinds ofmaterial, at least one kind of material consisting of a substantiallynon-allergenic self-adhesive material, the zones of material extendingsubstantially parallelly through the entire thickness of the product ina direction intersecting its flat surfaces wherein within a given zonethe composition of said material is substantially uniform.
 2. A skinbarrier product according to claim 1, wherein the zones of materialextend substantially at right angles to the flat surfaces of theproduct, from the surface adapted to contact the skin to the oppositesurface, and hence are of a length substantially the same as thethickness of the product.
 3. A skin barrier product according to claim1, wherein at least one zone is entirely surrounded at all edges by oneother zone.
 4. A skin barrier product according to claim 1, wherein atleast two kinds of material have been wound together to formneighbouring zones each substantially in the form of an Archimedeanspiral.
 5. A skin barrier product according to claim 1, wherein thezones of material, when seen from the surface of the product adapted tocontact the skin, each have a shape selected from rectilinear, curvedand wavy, which are substantially parallel and all extend from one edgeof the product to another.
 6. A skin barrier product according to claim5 wherein, at least one zone of material has a function other than anadhesive function.
 7. A skin barrier product according to claim 1,wherein at least one zone is entirely surrounded by a multiplicity ofother zones.
 8. A skin barrier product according to any of claims 1-6and 7 wherein at least one kind of zone consists of a self-adhesivematerial comprising a continuous phase containing a self-adhesiveelastomer mass and at least one hydrocolloid which is at least waterswellable substantially evenly distributed as a discontinuous phase inthe continuous phase.
 9. A skin barrier product according to claim 1wherein the units of material are substantially parallel alternatingstrips of identical or different widths.
 10. A skin barrier productaccording to one of claim 1 or claim 2, wherein at least one kind ofzone consists of a material which at least hampers the migration ofsolid, liquid and gaseous substances to and from neighbouringself-adhesive zones.
 11. A skin barrier product according to claim 10,wherein said zone consists of a material which at least hampers themigration of aqueous liquids to neighbouring hydrocolloid-containingself-adhesive materials.
 12. A skin barrier product according to claim11, wherein the material at least hampering the migration of solidliquid and gaseous substances is hydrophobic and ductile under theinfluence of small forces and contains a self-adhesive elastomer massbut no hydrocolloid.
 13. A skin barrier product according to claim 11,wherein the zones at least hampering the migration of solid, liquid andgaseous substances are at least one of films or foils of at least one ofplastic, metal or laminates thereof.
 14. A skin barrier productaccording to any one of claim 1, claim 2 or claim 7, wherein each zoneof material is a short strand extending from the flat surface adapted tocontact the skin to the opposite flat surface and each strand has across-sectional shape and size, when viewed in a plane parallel to saidflat surfaces, such that a multiplicity of such strands togethersubstantially fill up the product.
 15. A skin barrier product accordingto any one of claims 1, 2 or 3 comprising a continuous phase containinga self-adhesive elastomer and at least one hydrocolloid which is atleast water swellable and is substantially evenly distributed therein asa discontinuous phase; and a plurality of strands of a differentmaterial variously disposed through said continuous phase and extendingfrom the flat surface adapted to contact the skin to the oppositesurface, said self adhesive material substantially filling up theinterstices between said strands.
 16. A skin barrier product accordingto claim 1 in the form of a blank for the production of an annular padfor attaching drains, ostomy pouches or other equipment to a mammalbody, wherein the alternating zones of material are co-axiallycylindrical, and in that the product is provided with a centralaperture.
 17. A skin barrier product according to claim 16, wherein saidblank is provided on its outer edge and its inner edge with awater-impermeable barrier layer.
 18. A skin barrier product according toclaim 1 wherein at least one of the kinds of zones contains one or morebiologically active substances.
 19. A skin barrier product according toclaim 18, wherein said biologically active substance is selected fromthe group consisting of substances effective against warts,keratolytically active substances and mitosis-hampering compounds.
 20. Askin barrier product according to claim 1 wherein at least one kind ofzone possesses the property of transporting liquids in the thicknessdirection of the product.
 21. A skin barrier product according to claim1 wherein at least one zone consists of a self-adhesive material withouta hydrocolloid and at least one zone consists of an electricallyconductive hydrophilic gel substance.
 22. A skin barrier product asdefined in claim 8 wherein said hydrocolloid is water soluble.
 23. Askin barrier product according to claim 1, wherein the zones of materialare substantially alternating strips.
 24. A skin barrier product asdefined in claim 15 wherein said hydrocolloid is water soluble.
 25. Askin barrier product according to claim 1 in the form of a blank for theproduction of an annular pad for attaching drains, ostomy pouches andother equipment to a mammal body, wherein the alternating zones ofmaterial form an Archimedean spiral, and in that the product is providedwith a central aperture.
 26. A skin barrier product according to claim 1in the form of a blank for the production of an annular pad forattaching drains, ostomy pouches and other equipment to a mammal body,wherein the alternating zones of material are coaxial and cylindricaland surround a central aperture.
 27. A skin barrier product according toany one of claims 1, 2 or 3, comprising a plurality of strands composedof a self-adhesive material comprising a continuous phase containing aself-adhesive elastomer and at least one hydrocolloid which is at leastwater-swellable and is substantially evenly distributed therein as adiscontinuous phase, said plurality of strands extending from the flatsurface adapted to contact the skin to the opposite surface and beingembedded in a different material filling up the remainder of the skinbarrier product.
 28. A skin barrier product according to claim 26,wherein said blank is provided on its outer edge and its inner edge witha water-impermeable barrier layer.